Coating compositions comprising polyureas are used in a wide variety of industries such as automotive, watercraft, aircraft, industrial, construction, military, recreational equipment including sports equipment and the like. In these industries, considerable efforts have been made to develop coating compositions that will impart the desired properties to the substrate or article being coated. For example, coatings are used to protect against damage due to corrosion, abrasion, impact, chemicals, ultraviolet light, flame, heat and/or other environmental exposure. In addition to any of these functional properties, coatings can also be used for decorative purposes.
Polyureas are generally formed by reacting amines and isocyanates. The use of amines such as polyamines as crosslinkers or “curatives” is well known. For example, amines are known to crosslink with isocyanates to form urea compounds. Amines are also known to be reactive with, and therefore used with, activated unsaturated groups, epoxy groups, aromatic activated aldehyde groups, cyclic carbonate groups, and acid and anhydride and ester groups. Polyamine crosslinkers with primary amino groups can be quite reactive with some of these functionalities under ambient or low temperature conditions (i.e. less than 100° C.). This high reactivity can result in too short a potlife or other difficulties in application, such as in high pressure impingement spraying. Certain aliphatic secondary amines, however, are not reactive enough with these various functionalities. It is therefore desired to provide amine curatives that are sufficiently reactive, but that provide an adequate potlife. There is a further desire to provide such amine curatives that impart the desired characteristics to the final composition in which they are used.